The present invention relates to a system for automatically controlling gear transmissions, and more particularly to an automatic control system for an automatic gear-shifting system including a gear transmission.
In the prior art, there have been proposed various kinds of automatic gear-shifting systems for automatically shifting a gear transmission. For example, Japanese Patent Application Public Disclosure No. Sho 60-175854 discloses an automatic gear-shift control system of this type in which a gear-shifting actuator device including a plurality of solenoid valves is coupled with a gear transmission for operating the same and the opening/closing states of these solenoid valves are controlled in response to a signal from a control unit including a computer, whereby the gear-shifting operation of the gear transmission is automatically carried out.
In most conventional systems of such type, the associated internal combustion engine is also electronically controlled by the same control unit as that for controlling the gear transmission, and the control unit is mounted at a safe place in the vehicle. This means that the control unit stores both data specifically related to engine operation and data specifically related the operation of the gear transmission. Therefore, since control units are used in many types of vehicles with various different combinations of engine and gear transmission, it is necessary to provide many kinds of control data for storage in the computerized control unit. Manufacturers thus have to provide many kinds of control units. This increases manufacturing and maintenance costs.